Method and apparatus for utilizing amplitude-modulated pulse-width modulation signals for neurostimulation and treatment of neurological disorders using electrical stimulation

ABSTRACT

A computing device-controlled system is described for the generation of amplitude-modulated pulse-width modulation (AMPWM) signals for use in treating neurological dysfunction via cranial neurostimulation, where the AMPWM signal is specifically designed to minimize the electrical impedance of the tissues of the head. A low-frequency carrier signal is determined for the AMPWM signal by measuring EEG activity at a reference site or sites, generally corresponding with the location of suspected brain dysfunction. Carrier signal frequency is variably related to critical frequency components of the EEG power spectral density, determined from statistical analysis of amplitudes and variability, and dynamically changed as a function of time to prevent entrainment. The AMPWM signal is presented to a subject via a plurality of neurostimulation delivery modes for therapeutic use.

CROSS REFERENCE TO RELATED PATENT DOCUMENTS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/353,234, filed on Feb. 4, 2002, which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of producingand applying electrical energy to the brain, and to the therapeutic usesof the electrical energy and an apparatus for administering the same.More specifically, the present invention relates to a system forcontrolling neurostimulation where the neurostimulation comprises anelectrical signal whose characteristics minimize composite tissueimpedances of the head, and more specifically yet, to a computercontrolled system for automatic adjustment of neurostimulation signalsrelated to critical frequency components of an acquired EEG signal,generally obtained at or near a region of suspected brain dysfunction.

[0003] The electrical activity, or EEG, of human brains hastraditionally been used as a diagnostic marker for abnormal brainfunction and related symptomatic dysfunction. Often, traumaticdisturbances such as mechanical injury, social stress, emotional stressand chemical exposure cause neurophysiological changes that willmanifest as EEG abnormalities. However, disruption of this abnormal EEGactivity by the application of external electrical energy, henceforthreferred to as a neurostimulation signal, may cause yet furtherneurophysiological changes in traumatically disturbed brain tissues, asevidenced in an amelioration of the EEG activity, and hence arebeneficial to an individual. Such therapeutic intervention has provenuseful in pain therapy and in treating a number of non-painfulneurological deficits such as depression, attention deficit disorder,and many others.

BACKGROUND OF INVENTION AND DESCRIPTION OF RELATED ART

[0004] In the 1960's and early 1970's, Robert Monroe of the MonroeInstitute of Applied Sciences explored the effects of sound on the brainand discovered that he could produce a driving or entrainment of brainwaves. Dr. Gerald Oster, a biophysicist, also investigating the effectsof sound on the brain, discovered that pulsations called binaural beatsoccurred in the brain when tones of different frequencies were presentedseparately to each ear. The beat frequency equals the frequencydifference between the two tones. Both Monroe and Oster began usingelectronic oscillators to provide tones with frequency, purity andintensity that can be precisely controlled.

[0005] U.S. Pat. No. 3,884,218 to Robert A. Monroe shows a method forinducing sleep by amplitude modulating a pleasing sound with adelta-rhythm signal that is referred to as an “EEG sleep signal.” The'218 patent uses sound to induce sleep by creating a specific signalthat coaxes the brain into a relaxed state. This signal chosen in the'218 patent is chosen based upon its proximity to signals that arestrong during normal sleep.

[0006] U.S. Pat. No. 4,191,175 to Nagle shows a method and apparatus forrepetitively “producing a noise-like signal for inducing a hypnotic oranesthetic effect . . . ” by creating frequency bursts of digital pulsesthat are then passed through a pink noise filter to eliminatefrequencies above a certain cut-off. The resultant signal is then passedthrough a band pass filter and used to drive an audible signal source.

[0007] An apparatus for electrophysiological stimulation is shown inU.S. Pat. No. 4,227,516 to Meland et al. in which a first signal abovethe delta-beta frequency range is modulated by signal within that rangeand applied to electrodes on the forehead of a user.

[0008] A learning-relaxation device of U.S. Pat. No. 4,315,502 has bothlights for pulsing signals and sound means for a pulsing sound signal aswell as a control means that can individually vary the light and soundsignals.

[0009] U.S. Pat. No. 4,834,701 to Masaki shows a device similar to thoseused by Monroe and Oster with first and second generators withfrequencies above 16 hertz and a frequency difference of 4 to 16 hertzsounded to lower the brain wave frequency of a user. The term“entrainment” began to be accepted for such devices: “This phenomenon,in which one regular cycle locks into another, is now calledentrainment, or mode locking.” (Gleick, Chaos: Making of a New Science1987, Penguin Books, p. 293). An article entitled “Alpha Brain Waves &Biofeedback Training” in the December 1972 Popular Electronics show asystem that uses a person's own EEG signal to modulate a tone generatorwhich, in turn, then drives a speaker heard by the same person. Thedevice allowed a person to “hear” his or her own brain signals in anattempt to voluntarily control the frequency. A similar device thatallows a person to “see” his or her own brain waves is shown in anarticle entitled “Mind Power: Alpha” in the July 1976 Radio-Electronics.

[0010] U.S. Pat. No. 5,036,858 to John L. Carter, Harold L. Russell andLen Ochs shows the use of EEG electrodes attached to the head of theuser along with an amplifier for determining a current brain wavefrequency of a user, which is communicated to a computer processor. Anew frequency is generated which is between the current brain wavefrequency and a desired brain wave frequency and is within apredetermined range of the current brain wave frequency. This has becomeknown as electroencephalographic entrainment feedback if it is used to“lock” the current brain wave frequency into a desired frequency.

[0011] U.S. Pat. No. 5,365,939 to Len Ochs provides a method of“exercising” the brain by using a device producing audio and visualstimulation to move a user's brain wave frequency back and forth betweenpredetermined frequency levels.

[0012] In U.S. Pat. No. 6,081,743 to John L. Carter, Harold L. Russell,W. Daniel Vaughn and Robert R. Austin, a method for treating anindividual is described by determining a brain wave frequency whichcorresponds to a highest evoked response of the individual, entrainingthe brain wave frequency to the brain wave frequency corresponding tothe highest evoked response, and then maintaining the brain wave at thatfrequency for a predetermined length of time. The highest evokedresponse is described as the highest EEG response or the highestcerebral blood flow (CBF) of the individual or even some other measure.

[0013] Two patents in application at the time of the disclosure of thepresent invention relate to the present invention. In Application No.20010003799 by Birinder B. Boveja an apparatus and method for adjunct(add-on) therapy utilizing an external stimulator is described tostimulate a cranial nerve according to a predetermined program.

[0014] In Application No. 20010007950 by Richard B. North et. al. aneurostimulation system and method is described that includes animplantable stimulator and patient interactive computer. Also, the '950application requires patient interaction.

[0015] Prior methods of neurostimulation for therapeutic purposes havein many ways attempted to ameliorate brain functioning by providing thebrain with electrical energy that is designed to be a reflection of thebrain's own activity, often with the intent of modifying the brainelectricity to follow, or entrain to, a desired frequency, range offrequencies, or relationship among frequencies, or alternately to targettheoretically and empirically derived frequency states as a goal oftraining or therapy. However, little attention has been given to signaldesign for overcoming the complex and composite impedance presented bythe tissues of the head. Such signals, when properly constructed, willlimit attenuation of neurostimulation signals for improved effectivenessin patient treatment.

[0016] Regarding the concept of conductivity, it is known that thetendency of any conductive material to limit the flow of electricalcharge, otherwise known as electrical current, is known as impedance. Ingeneral terms, attenuation of current flow is proportional to themagnitude of a material's impedance. The impedance of a substance is afunction of its material and physical properties. Environmental factors,such as temperature, also influence the impedance of a material. Mostsignificant to the disclosure of the present invention is therelationship between impedance of a material and the frequency of theelectrical signal being conducted through the material.

[0017] In its most fundamental terms, three electrical effects governimpedance: resistance, capacitance and inductance. Resistance is afundamental form of impedance that is constant in time. Therefore, thefrequency of a signal has no effect on resistance. However, bothcapacitive and inductive effects are functions of frequency. Inductivereactance, the formal name for impedance due to inductance, isproportional to frequency. Thus, the higher the frequency of a signalis, the higher will its corresponding inductive reactance be. Capacitivereactance, the formal name for impedance due to capacitive effects, isinversely proportional to frequency. Thus, as a signal's frequencyincreases, the impedance of a material due to capacitance decreases. Forvery high frequencies, capacitive reactance can become very small, andthe resulting attenuation of the flow of current will be correspondinglyless.

[0018] The head is comprised of a series of tissues that can beapproximately thought of as composite layers surrounding the brain.Specifically, these layers of tissue include the dermal layers of thescalp, the skull, the meninges, the cerebral spinal fluid that bathesthe brain, and the brain itself including both healthy tissues andunhealthy tissues such as lesion matter forming in the region of damage.The impedance of the tissues of the head is known to be complex innature, that is, they have both a resistive component and a capacitivecomponent. Thus, the overall impedance of these tissues will be afunction of signal frequency because of capacitive reactance, and anelectrical circuit model of these impedances must account for this fact.Because of the nature of this impedance, a higher frequency signal willpass through the tissues with much less attenuation.

SUMMARY OF THE INVENTION

[0019] The present invention is based on the discovery that certainneurostimulation signals can provide an optimal effect on the tissues ofthe brain, while eliminating conscious patient perception of the signal.

[0020] Thus, the invention is directed towards a method of treating oneor more neurological dysfunctions. The method comprises taking a firstmeasurement of the EEG of a subject afflicted with at least one type ofthe neurological dysfunction in order to obtain EEG results andevaluating the EEG results to determine whether any region of thesubject's brain possesses irregular activity as compared to otherregions of the subject's brain. A determination of a dominant frequencyis separately made for each of the regions of the subject's brain thatpossess irregular activity by examining the EEG results from each theregions of the subject's brain that possess irregular activity. Finally,the method comprises an administration of an anti-neurologicaldysfunction therapy to the subject. The anti-neurological dysfunctiontherapy comprises inducing a neurostimulation signal directed to theregions of the subject's brain that possess irregular activity for atime sufficient to normalize the EEG of the regions of the subject'sbrain that possess irregular activity. Additionally, further EEGmeasurements from the regions of the subject's brain that possessirregular activity are monitored during the administration of thetherapy and the neurostimulation signal is adjusted based on anydetected changes in the additional EEG measurements.

[0021] The invention is also directed to an apparatus forneurostimulating a subject. The apparatus comprises a computing devicethat is operatively coupled to a neurostimulator, and a series of EEGsensors that are coupled to the neurostimulator. The EEG sensors areconfigured (1) to be attached to the subject, (2) to monitor EEG resultsof a subject, and (3) to administer neurostimulation signals to thesubject. Additionally, the EEG sensors preferably comprise at least onepositive contact, at least one negative contact, and at least one groundcontact.

[0022] In accordance with the disclosure herein, an object of thepresent invention is to generate an electrical signal for the purposesof neurostimulation that also minimizes the effect of tissue impedanceto the improved flow of electrical energy to body tissues.

[0023] It is a further object to pass extremely low power signals withminimal attenuation into subjects who possess a high sensitivity toneurostimulation signals.

[0024] It is a further object to use an electrical signal referred to asan amplitude-modulated pulse-width modulation (AMPWM) signal. An AMPWMsignal is characterized by a high frequency component that is modulatedby a low frequency carrier for stimulation purposes.

[0025] It is a further object to use pulse-width modulation and/oramplitude control of the high frequency component of the AMPWM signal inorder to control the electrical energy level present in aneurostimulation signal.

[0026] It is a further object of the present invention to use an AMPWMsignal in neurostimulation in order to disentrain an EEG signal.Disentrainment involves the prevention of the EEG signal from lockinginto a particular frequency or frequency range, and to cause, rather,the redistribution of EEG spectral energy. Additionally, it is an objectof the present invention for the AMPWM signal to not maintain a givenfrequency for a period of time sufficient to cause dysfunctionalentrainment such as that which occurs in an epileptic seizure.

[0027] A further object of the present invention is to provide a meansof constantly assessing power spectral density or other frequencyrelated statistics of EEG signals, and using the frequency relatedstatistics from the EEG signals to manage the low frequency component ofan AMPWM neurostimulation signal so as to prevent entrainment to anyspecific frequency, and to distribute energy uniformly.

[0028] A further object is to provide a means of entraining EEG signalsby controlling the low-frequency component of an AMPWM neurostimulationsignal.

[0029] A further object is to provide a means of controlling the lowfrequency component of an AMPWM signal so that the frequency of the lowfrequency component is determined as a function of either a constantoffset in time or a frequency analysis driven offset determined as afunction of time.

[0030] Another object of the present invention is to provide a means ofdelivering a neurostimulation signal to regions of the scalpcorresponding to suspected regions of brain dysfunction by inducing theneurostimulation signal into EEG sensors that are concurrently used formeasurement of EEG signals.

[0031] Another object of the present invention is to provideneurostimulation in which electrical currents are passed throughsuspected regions of brain dysfunction through EEG sensors which areplaced in a manner so that the region of the brain of the subject inwhich a dysfunction is located is in the area of placements of EEGsensors.

[0032] Another object is to provide for the utilization of an AMPWMsignal for delivery of neurostimulation through a photic means, such asrapid pulsing of light-emitting diodes, in which the light intensity iscontrolled by pulse width modulation of the high frequency component ofthe AMPWM signal.

[0033] Another object of the present invention is to provide a means ofmodifying the low-frequency component of an AMPWM signal to relate tofrequency components of EEG signals, the means being accomplished by anynumber of frequency analysis techniques.

[0034] Another object is to provide a system for neurostimulation thatincludes a means for acquiring EEG signals from a subject, analyzing theEEG signals for frequency components and generating an AMPWM signalwhich is delivered to the subject for either the disentrainment or theentrainment of EEG activity of the subject for therapeutic purposes.

[0035] Another object is to provide a means of determining suspectedregions of brain dysfunction in a subject by acquiring EEG data from anumber of scalp sites of the subject, analyzing the EEG data forfrequency components and assignment to standard bands of EEG (e.g.delta, theta, etc.), determining the electrical energy in each of thestandard bands by analysis in order to determine a statistic that is afunction of total power in the band to include but not limited to sum ofamplitude, or root-mean-square, or root square summation; andvariability to include but not limited to variance or standarddeviation, and using the statistic magnitude as a function of EEGfrequency range as an indicator of brain dysfunction.

[0036] A further object is to provide for an enhanced means ofdetermining brain dysfunction related to patient symptoms by measuringsites correlating to known systemic functions (e.g. pain, speech,movement) and performing the previously described statistical analysis.

[0037] A further object is to provide a means of using the statisticsobtained from the previously described statistical analysis to create avisual graphic corresponding to regions of the brain for comparativepurposes.

[0038] A further object of the present invention is to provide a meansof delivering neurostimulation by using more than one EEG amplifier formulti-site neurostimulation, and wherein an AMPWM signal is deliveredeither via photic means or directly to suspected regions of braindysfunction via EEG sensors operatively coupled with an EEG amplifier.

[0039] A further object of the present invention is to provide methodsof controlling neurostimulation signal parameters such as signal energylevel, frequency of the low frequency component of an AMPWM signal,phase offset of multiple signals, start time and duration through a userinterface.

[0040] A further object is to provide for selection of aneurostimulation delivery mode.

[0041] A further object is to provide a method of assuring EEG leadinterface integrity, for both EEG acquisition purposes andneurostimulation purposes, by testing using an algorithm to analyze ameasure EEG signal to determine lead interface integrity. This algorithmdetects random electrical noise, which is a sign of poor interfaceintegrity.

[0042] A further object of the present invention is to provideneurostimulation for other purposes of enhancing brain activity, such asbrainwave training.

[0043] A further object is to provide a means of correlating EEG data toobserved events and/or perceived events by provision of an interfacecontrol for marking data either by a patient or a clinician duringneurostimulation.

[0044] These and other objects, advantages and features of thisinvention will be apparent from the following description taken withreference to the accompanying drawings, wherein is shown a preferredembodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0045]FIG. 1 illustrates a view of the apparatus.

[0046]FIG. 2 illustrates a graphic representation of theneurostimulation signal. It is a representation for illustrativepurposes only and it is not intended to limit the scope of the signalused in the present invention in any way.

[0047]FIG. 3 presents a model of the apparatus of the present inventionin regards to tissue impedance.

[0048]FIG. 4 illustrates another view of the apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] The present invention is directed towards a method and anapparatus suitable for the treatment of neurological dysfunctions.

[0050] The term “optical unit” is intended to define an apparatus thatis used on or in close proximity to the eyes. By close proximity, it ismeant a distance from the eyes of a subject that is effective for thetransmittal of a light pulse into the eyes of the subject. Preferably,close proximity will not exceed one foot in distance from the subject.The structure of the optical unit may be worn on the face of thepatient, such as optical device or goggles, or it may be located in aseparate structure, such as a stand that is held near the face or even ahand-held mask. Further, the optic unit may be placed at an angle to theeyes of the subject. Additionally, the optic unit may be positionedbehind the subject and use mirrors or other reflective devices (such asa white wall) to reflect the light pulse into the eyes of the subject.However, in no way is this definition intended to limit the ultimatestructure the optical unit may take.

[0051] The term “neurological dysfunction” is intended to define a groupof disorders in which one or more regions of a subject's brain operateat frequencies which are different from the predetermined frequency forthat region of the brain or from the predetermined frequencies of theother regions of the subject's brain. Examples of neurologicaldysfunctions include traumatic brain injury, post traumatic stressdisorder, post stroke paralysis, post traumatic brain injury paralysis,cerebral palsy, headache, depression, post chemotherapy cognitive, moodand fatigue disorder, fibromyalgia, memory loss, coma, attention deficitdisorder, etc. However, the present invention is not to be construed asbeing limited to the treatment of these listed examples.

[0052] The term “irregular activity” is intended to define the EEGfrequency of an region of the subject's brain which does not match thepredetermined EEG activity of the remaining regions of the subject'sbrain. Additionally, the term “irregular activity” is also intended todefine an EEG frequency of an region of the subject's brain that matchesthe EEG activity of the remaining regions of the subject's brain, butwith a high degree of variance. Irregular activity is determined byanalyzing the frequency bands of the region of the brain beinginvestigated and identifying either a higher band amplitude or a lowerband amplitude than is predetermined for that region. Examples ofpotential irregular activity include amplitude abnormalities in whichthe measured peak-to-peak microvolts is over 14 microvolts (abnormallyhigh) or in which the measured microvolts is under 5 volts frompeak-to-peak (abnormally low) or possesses a standard deviation of over3 microvolts. However, these are examples only. One of ordinary skillwould recognize what a proper benchmark would be for each subject.

[0053] The term “neurostimulation signal” is intended to define a signaltransmitted by the neurostimulator to a subject for the purpose ofnormalizing the brainwave activity of regions of the subject's brainthat possess irregular activity. The neurostimulation signal isdetermined on a subject by subject basis and is changed in relation to ashift in the region's dominant frequency. There is typically a reductionin variability as EEG changes occur. This is evidenced by a shift in thedominant frequency more towards the typical frequencies and amplitudesthat were predetermined for that region of the subject's brain.

[0054] The term “normalization” is intended to define the result of theadministration of a neurostimulation signal to regions of the subject'sbrain that correspond to the regions of the subject's brain that possessirregular activity. The neurostimulation signal is intended to“normalize” or adjust the brainwave frequency of the regions of thesubject's brain that possess irregular activity to reflect thepredetermined frequency of the region of the subject's brain that isbeing treated.

[0055] The term “dominant frequency” is intended to define the frequencyin the EEG measurements taken from an area of the subject's brain thatpossesses the highest voltage amplitude.

[0056] The present invention is directed towards the alleviation ofsymptoms of neurological disorders caused by irregular EEG activity in asubject's brain. The alleviation of the symptoms is accomplished byadministering a neurostimulation signal to the regions of the subject'sbrain that are related to those regions of the subject's brain thatpossess irregular activity. These related regions of the subject's braincan include regions that possess irregular activity, or other regions ofthe brain. One of skill in the neurological arts would recognize whichregions of the brain are interrelated with other regions of the brain.

[0057] For example, in one method of choosing the treatment sites, thechoice is determined by the regions of EEG-slowing specific to anindividual, regardless of the diagnosis. In this method, it is thepresence and pattern of EEG-slowing at any of the standard neurological10-20 sites (as selected by the International 10-20 EEG Site PlacementStandard) that is the indication of the appropriateness of an region ofthe brain for treatment. The EEG-slowing pattern also determines whereon the scalp electrodes will be placed for treatment.

[0058] Because EEG slowing that is associated with fatigue, poorshort-term memory, and attention problems is likely to involvefunctional deficits in the left frontal lobes of the brains, placingelectrodes on any of the following sites is a reasonable directive: FP1,F7, F3, C3, F1, AF7, F5, AF3 and possibly temporal sites, T3 & T5(according to the International 10-20 EEG Site Placement Standard). Theamplitudes and standard deviations from the image data determine theorder of treatment for these sites.

[0059] The imaging data is preferably gathered by sequentially recordingfrom each of 21 sites. These data are preferably processed through aFast Fourier Transform (FFT) computation which produces quantitativedata that shows the average microvolts and the standard deviation foreach frequency component of the EEG signal at each site. A preferredmethod of treatment is to identify those sites that have the higheststandard deviation as shown in the FFT results and treat them first.Treatment can be accomplished by placing two pairs of electrodes (onepositive and one negative comprise a pair) on each of the four siteshaving the highest measured amplitudes.

[0060] It is the unique EEG pattern of the individual, however, that isthe key to the most efficient treatment. The determination of treatmentsites applies to any diagnostic category of neurological dysfunction andthe determination is individualized by the quantitative data from eachindividual's brainwave data. Therefore, it is not possible to specify astandard set of sites for any given, or all, diagnostic categories.However, there is a broad diagnostic classification called EEG-slowingand that this category can permit the selection of predetermined sitesfrom which to direct the treatment of choice. Therefore, given the aboveinformation one of ordinary skill would understand how to select aregion of the brain for treatment on a subject by subject basis.

[0061] The neurostimulation signal is administered by modulating a highfrequency component, which can be further pulse-width modulated forcontrol of the energy level, with a low frequency carrier. It is thepreferred intent of the present invention to “disentrain” the brain'selectrical activity, that is, to not target or lock into a particularfrequency, but rather to redistribute existing energy to all frequenciesin the normal spectra of the brain EEG in a typically uniform manner.However, the present invention does not preclude the utilization of theneurostimulation signal for the purposes of entrainment.

[0062] The present invention also embodies a method of focusing aneurostimulation signal directly on a suspected dysfunctional region ofthe brain. This is possible because tissue impedances are minimized bythe design of the neurostimulation signal. The neurostimulation signalpossesses a greater ability to directly reach damaged regions of thebrain rather than simply following the outer-most tissues around thescalp and thereby bypassing the damaged region of the brain. Anotheradvantage is achieved by inducing the neurostimulation signal directlyinto EEG sensors. This advantage is that the neurostimulation signal canbe strategically placed to present a conduction path through the damagedregion of the brain, while concurrently measuring the EEG signal at thedysfunctional regions, thus providing a direct link between the measuredEEG signals and the neurostimulation signals being delivered directly tothe dysfunctional region.

[0063] A method for treating a subject with the method of the presentinvention preferably includes the generation of an electricalneurostimulation signal characterized by a high frequency pulse trainmodulated by a low frequency carrier signal. A means of providing forvariable levels of electrical power may be accomplished by using eitherpulse width modulation of the high frequency pulse train, as in thepreferred embodiment of the present invention, or variable amplitudes ofthe same pulses. Preferably, the frequency of the high frequency pulsetrain is at least one order of magnitude greater than the frequency ofthe low frequency carrier signal. It is preferred that the highfrequency pulse be in the range of 43 to 1,000,000 hertz. It is morepreferred that the high frequency pulse be in the range of 1,000 to100,000 hertz. It is even more preferred that the high frequency pulsebe in the range of 10,000 to 20,000 hertz. It is most preferred that thehigh frequency pulse be 15,000 hertz.

[0064] The low frequency carrier signal is variably related to criticalfrequency components of the EEG power spectral density, determined fromstatistical analysis of amplitudes and variability. The low frequencycarrier signal is determined from information obtained by measuring EEGactivity at a reference site or sites that generally corresponds withthe location of suspected brain dysfunction, and the low frequencycarrier signal is dynamically changed as a function of time to prevententrainment. This is performed by changing the frequency offset (asdescribed below) at predetermined time intervals. It is preferred thatthe low frequency carrier signal be typical of a brainwave EEG. It ismore preferred that the low frequency carrier signal be in the range of142 hertz.

[0065] The combination of (1) the high frequency pulse train as it ismodulated by (2) the low frequency carrier signal, henceforth referredto as an AMPWM signal, provides a means of minimizing the effect oftissue impedances of the head. However, no limitation of the presentinvention to AMPWM signals alone is intended by this abbreviation. Anysignal that possess both (1) and (2) as defined above is intended to beencompassed by the present invention.

[0066] In general, as will be discussed in greater detail in subsequentsections of this disclosure, the electrical impedance of tissues of thehead decreases with increased electrical signal frequency. Thus, thehigh frequency pulse train component of the AMPWM signal passes throughthe head tissues with less attenuation than the low frequency carriersignals typically used in already known neurostimulation methods.Further, the low frequency carrier signal component of theneurostimulation signal in essence serves to turn on and off the highfrequency signal component with a frequency that is generally related tothe range of frequencies present in an EEG signal. Thus, the lowfrequency carrier signal component may be produced at frequenciescommonly used for therapeutic purposes in neurostimulation devices, suchas entrainment or disentrainment.

[0067] Some neurological dysfunctions that may be treated by the presentinvention include traumatic brain injury, post traumatic stressdisorder, post stroke paralysis, post traumatic brain injury paralysis,cerebral palsy, headache, depression, post chemotherapy cognitive, moodand fatigue disorder, fibromyalgia, memory loss, coma, attention deficitdisorder, etc. However, this list is not intended to be exclusive.

[0068] The method preferably comprises taking a first measurement of theEEG of a subject afflicted with at least one type of the neurologicaldysfunction in order to obtain EEG results and evaluating the obtainedEEG results to determine whether any region of the subject's brainpossesses irregular activity as compared to other regions of thesubject's brain. It is preferred that the subject be a mammal and, morepreferably, a primate. It is most preferred that the subject be a humanbeing. It is also preferred that the irregular activity be determined bycomparing the EEG signals from a region of the subject's brain with theEEG signals from the remaining regions of the subject's brain. It isalso preferred that the EEG signals are obtained from more than oneregion of the subject's scalp. It is even more preferred that the EEGsignals be obtained from at least 21 regions of the subject's scalp thatcorrespond to 21 regions of the subject's brain. It is preferred thatthe regions be selected according to the International 10-20 EEG SitePlacement Standard.

[0069] A determination of a dominant frequency of the subject's brain ismade from the evaluating the EEG results from the regions of thesubject's brain that possess irregular activity. Preferably, theevaluation involves the correlation of the EEG signals into a graphicimage of the subject's brain. Even more preferably, the graphic image isevaluated and new EEG signals from the subject's brain are taken inorder to ensure that the first EEG signals were accurate and in order todetermine a dominant frequency from the regions of the subject's brainthat have been confirmed as possessing irregular activity.

[0070] Finally, the method comprises an administration of ananti-neurological dysfunction therapy to the subject. Theanti-neurological dysfunction therapy comprises inducing aneurostimulation signal directed to the regions of the subject's brainthat possess irregular activity for a time sufficient to normalize theEEG signals of the regions of the subject's brain that possess irregularactivity.

[0071] It is preferred that the time be between one second and one hour.It is more preferred that the time be between 1 and 30 minutes. It iseven more preferred that the time is between 1 minute and 10 minutes. Itis even more preferred still that the time be between 1 minute and 3minutes. It is still more preferred that the time be between 1 secondand 30 seconds. It is most preferred that the time be between 1 secondand five seconds

[0072] Additionally, further EEG signal measurements from the regions ofthe subject's brain that possess irregular activity are monitored duringthe administration of the therapy and the neurostimulation signal isadjusted based on any detected changes in the additional EEG signalmeasurements. The normalization of the EEG signals from the regions ofthe subject's brain that possess irregular activity results in analleviation of the symptoms of the neurological disorders.

[0073] The neurostimulation signal comprises a carrier frequency whichcomprises the dominant frequency and the frequency offset. It ispreferred that the frequency offset be between −10 and 20 hertz.

[0074] It is preferred that the normalization of the regions of thesubject's brain that possess irregular activity result in these regionstransmitting EEG signals which are close to the predetermined frequencyand amplitude expected for those regions of the subject's brain. It iseven more preferred that these regions transmit EEG signals at thepredetermined frequency and amplitude expected for those regions of thesubject's brain after the treatment.

[0075] The subject may require multiple exposures to the method in orderto achieve an alleviation of the symptoms he or she suffers from theneurological dysfunctions. It is preferred that the multiple exposuresremain in the range of 1 to 40 exposures. However, more exposures arepermitted, if required. It is more preferred that the exposures remainin the range of 10 to 30 exposures. It is more preferred that theexposures remain in the range of 5 to 10 exposures. Additionally, it ispreferred that a repeated use of the method be avoided within 24 hoursof a previous use of the method. However, if required, it is possible totreat more than one region of the subject's brain (if more than oneregion of the subject's brain possesses irregular activity) in onetreatment session.

[0076] Additionally, the subject may be medicated, sedated, orunconscious during the administration of the method. However, it ispreferred that the subject be in none of these conditions.

[0077] Regarding the application of the neurostimulation signal itself,after the identification of regions the subject's brain which possessirregular activity, neurostimulation treatment is accomplished byplacing EEG sensors in an arrangement that allows for the measurement ofthe EEG activity from the dysfunctional region, as well for providing asuccessful delivery of current from the EEG sensors into a systemground. The computer-controlled system in the preferred embodiment ofthe present invention acquires EEG signal data from the sensor sites andconducts an analysis of the EEG signal data to determine the frequencyof the low frequency carrier signal component of the AMPWM signal.

[0078] The AMPWM signal can be transmitted to the subject through aplurality of neurostimulation delivery modes. In a preferred embodimentof the present invention the preferred mechanism of delivery isaccomplished by inducing the AMPWM signal into the EEG sensors throughinductive coupling. Another preferred mechanism is to use the AMPWMsignal to drive a light-generating component, such as a light emittingdiode, to provide a photic stimulation signal that may be delivered tothe patient through the optic nerve.

[0079] Another preferred embodiment involves the simultaneous use ofstimulation delivery by inducing the AMPWM signal into the EEG sensorsthrough inductive coupling and drive a light-generating component, suchas a light emitting diode, to provide a photic stimulation signal. Inessence, this is a combination of previously discussed embodiments.

[0080] Lastly, it is preferred that EEG leads be placed on the scalpregardless of what stimulation method is used because the apparatus andmethod preferably measures EEG during stimulation delivery, and usesthese EEG measurements to drive neurostimulation signal parameters.

[0081] In a preferred embodiment of the present invention, delivery modeis selectable to account for different levels of sensitivity andtolerance in patients. It is also possible to completely automate theprocess of transmitting the neurostimulation signal and the monitoringof the EEG signal data from the EEG sensors.

[0082] As stated above, it is preferred that the EEG signals from thesubject be measured at typically 21 different scalp locations and it ispreferred that power spectral density computations are performed on theobtained EEG signals. These computations break the measured analog EEGsignals into frequency domain data such as a Fourier series of discretefrequency components, which is limited to 1-42 Hertz (greater signalcomponents exist and could be utilized, but the 1-42 Hertz range istypically considered clinically useful). However, other methods ofobtaining the frequency domain data are acceptable (such as the use ofwavelet analysis).

[0083] In analyzing EEG signal data, frequency bands are commonly used.For example, the “delta” band is typically 1-4 Hertz, the “theta” bandis 5-7 Hertz, and so on. For each site, the total amplitude associatedwith each discrete frequency component is assigned to proper bands,providing a measure of the EEG band energy for each of theaforementioned sites. From this, a graphic “image” is generated wherecolors represent amplitudes. From this image, the clinician can see EEGband activity related to regions of the brain, and based on clinicalknowledge, can determine if a region has unusual or abnormal activity.

[0084] Accordingly, the neurostimulation phase of the process (i.e.treatment) is administered to correct regions of abnormal activity. Theadministration of the neurostimulation signal is preferably performedafter the imaging process described above is completed. The clinicianpreferably applies EEG sensors to regions of the scalp that relate tothe regions of suspected dysfunction and the EEG signal data ispreferably re-measured for a period long enough to provide powerspectral density data (as in the imaging process). The frequency domaindata is then sorted, and the frequency that exhibits the highestamplitude is designated the “dominant frequency”. According to clinicianchosen stimulation time and frequency parameters, a neurostimulationsignal is generated that has a “carrier frequency” that is determined bythe formula:

CARRIER FREQUENCY=DOMINANT FREQUENCY+FREQUENCY OFFSET

[0085] The parameters the clinician uses are (1) stimulation intensity,(2) the times that the stimulation signal is turned on in the treatmentcycle (as well as the number of times), (3) the duration that eachstimulation signal is turned on, the leading frequency of eachstimulation event, and (4) the phase offset of each stimulation event.Intensity is defined by the pulse-width-modulation duty cycle, andranges from 0 (no “on-time”) to 100% (no “off-time”). Thus, an intensityof 50% would have a duty cycle such that “on-time” is equal to“off-time” in each pulse cycle. The number of stimulation cycles and thetimes that the stimulation turns on is entirely clinician driven.However, it is preferred ranges that the stimulation cycles rangebetween 1 stimulation event up to 50. It is preferred, however, that nomore than 20 different stimulation events be used per session. Thepreferred leading frequency is already defined to range between −10 and20 Hz. Preferred Phase offset ranges from −180 to 180 Hz.

[0086] In this formula, “frequency offset” is preferably selected fromthe range of −40 to 40 Hertz and more preferably from −10 and 20 Hertz.

[0087] The offset is chosen by clinical experience, therefore, one ofordinary skill in the art would recognize how to choose an offset.However, the clinician generally picks the largest offset (i.e., +20 Hz)to see if a response is elicited. If no response is elicited, loweroffsets will be tried until a response is obtained. The clinician'schoice of parameter values is typically driven by a selection of choicesthat cause the subject to react, but yet do not cause an “over-reaction”which is an adverse effect characterized by short-term fatigue,headache, etc

[0088] All of the preferred neurostimulation parameters to be consideredare defined below. Values of these parameters are chosen based onclinician experience, and are selected in a manner that is meant tocause a reactive therapeutic effect without causing the subject toover-react. The selection of these values is further driven by subjectcondition and symptomatic presentation. For example, a subject with mildtraumatic brain injury may be able tolerate a longer (in duration) thanaverage stimulation application without suffering an adverse effect.However, a subject with Fibromyalgia with severe fatigue may onlytolerate a very short (in duration) stimulation burst at the lowestintensities possible. The ranges of values for these parameters areprovided for the clinician to choose based on experience, patientcondition and symptomatic presentation, thus no preferred or optimalvalues exist. These parameters include:

[0089] Intensity—This is a measure of the pulse width modulationsignal's duty cycle. This provides a variation on the time-averagedcurrent delivered to the stimulation mechanisms (i.e. the EEG leadinducing circuit and the photic stimulators).

[0090] Duration—This is a measure the time in seconds that aneurostimulation event (i.e. a period of stimulation signal output)lasts. This can range from 1 second to 1,200 seconds in the preferredembodiment.

[0091] Start Time—This is the time in seconds after the beginning of aneurostimulation treatment session begins when a neurostimulation eventstarts to occur. There is no specific limitation on this, that is, thestart time could begin at any time after the treatment session begins.Before the start time occurs, the system is simply measuring EEG andthis could, theoretically, go on indefinitely.

[0092] Leading Frequency and Phase Offset are previously defined.

[0093] By adding the frequency offset to the dominant frequency, acarrier frequency is created that is always different than the dominantfrequency. This neurostimulation signal is then either induced in theEEG sensors attached to the subject's scalp or the neurostimulationsignal is used to drive light emitting diodes for photic stimulationpurposes. The duration of the signal, along with other parameters (asdescribed above) such as intensity and phase offset (in the case of LEDsfor photic stimulation—a phase offset causes the LEDs to flash out ofsynchronization with each other) are determined by the clinician'schosen treatment protocol.

[0094] As described above, the neurostimulation signal can be anamplitude modulated pulse-width modulation signal. A graphicrepresentation of the signal is shown in FIG. 2. In other words, thecarrier frequency simply turns an electric signal on and off in a waythat a square-wave pulse train is generated with a frequency equal tothe carrier frequency. Thus, in a period (period =1/frequency) of thispulse train, there will be an amount of time that the electric signal is“on” and an amount of time when the signal is “off” (see FIG. 2). Duringthe time that the carrier signal is “on”, the electricity is furtherpulsed at a very high frequency. A pulse width modulator is used tocontrol this high frequency pulsing. By varying the pulse width, theaverage current applied is varied. This is what varying the “intensity”means. With a very low duty cycle, there is very little average currentand thus the neurostimulation signal has very low intensity. Conversely,a higher duty cycle delivers more current and thus the intensityincreases. A 100% duty cycle means that there is no “high frequency offtime”, and thus the entire neurostimulation signal is a simple squarewave pulse train with frequency equal to the carrier frequency.

[0095] Regarding the apparatus, FIG. 3 presents a model of the apparatusof the present invention. In FIG. 3., tissue impedance 6 is representedby a parallel combination of a simple resistor 1 and a simple capacitor2. A voltage source 3 provides electricity at a supply electrode 4interfaced at a subject's skin 7, with the electricity passing throughthe tissue impedance 6 and ultimately being returned to a common ground5 potential. Following fundamental circuit analysis, the equivalentimpedance (Z_(EQUIVALENT)) of the circuit is given by the formula:$Z_{EQUIVALENT} = \frac{R}{1 + {2\quad \pi \quad {fRC}}}$

[0096] In this formula, the resistance is given by the nomenclature R,capacitance by C and frequency by f. This equation clearly shows that asthe frequency of the signal increases, the overall impedance of thesystem decreases despite the level of impedance from the resistor 1being constant. Although the impedances of the composite tissues of thehead are considerably more complex and require a far more sophisticatedmodel to accurately describe current flows, this model provides a simpleanalogy and approximately describes the effect, and is a fundamentalbasis for the disclosure of the present invention.

[0097] The effects of applying electrical energy to brain tissues, theelectrical energy is known in this disclosure as a neurostimulationsignal, are well established in the medical literature and in otherteachings, and will not be expounded upon here.

[0098] As stated above, the invention is also directed to an apparatusfor neurostimulating a subject. The apparatus comprises a computingdevice that is operatively coupled to a neurostimulator, and a series ofEEG sensors that are coupled to the neurostimulator. Examples ofappropriate computing devices are microprocessors or computers. However,any processing unit can be used in the present invention as a computingdevice. These components are coupled to each other via electricalconduction paths. For example, the neurostimulator could be coupled tothe computing device with RS232 cable, USB cable, etc. Further, the EEGsensors can be coupled to the neurostimulator with an electricalconnector. However, in both instances, other methods of coupling thecomponents are acceptable. The EEG sensors are configured (1) to beattached to the subject, (2) to monitor EEG signals of a subject, and(3) to administer neurostimulation signals to the subject. Additionally,the EEG sensors comprise at least one positive contact, at least onenegative contact, and at least one ground contact.

[0099] The apparatus further comprises a biopotential acquisitiondevice, at least one filtering unit, an isolation amplifier, and amicrocontroller. A preferred microcontroller is the Toshiba TMP95FY64.However, any comparable microcontroller may be used. The biopotentialdevice is operatively coupled to the computing device, and theneurostimulator is configured to transmit the biopotential data and EEGsignal data to the biopotential acquisition device. These components maybe coupled together in the manner set forth previously or in anyadditional manner that permits their correct usage. Additionally, thebiopotential acquisition device is configured to transmit the EEG dataand biopotential data through at least one circuit or numerical filterand through an isolation amplifier which is operatively coupled to themicrocontroller. Furthermore, it is preferred that the isolationamplifier be capable of performing “notch” filtering (i.e., eliminate 60Hz line noise) and it can be selected from any component found on themarket. It is preferred that it be a Burr-Brown ISO-100.

[0100] It is preferred that the filtering unit be selected from thegroup consisting of a circuit configured to filter data and a numericalfilter. It is also preferred that the biopotential acquisition device isa biopotential amplifier or a high resolution analog-to-digitalconverter.

[0101] The neurostimulator comprises a biopotential acquisition unitcomprising an electric circuit configured to acquire biopotential datafrom the EEG signals obtained by the EEG sensors attached to thesubject. The biopotential acquisition unit is also configured to analyzeand store the acquired biopotential and EEG data with computationalmeans and it is operatively coupled to the neurostimulator. Theneurostimulator also comprises a transmission unit configured totransmit the biopotential and EEG data from the neurostimulator to thecomputing device and an I/O (input/output) unit configured to adjust fora time lag in the biopotential and EEG data being transmitted. Theneurostimulator also comprises at least one switching unit configured tomanage a neurostimulation signal.

[0102] It is preferred that the subject is a mammal. It is furtherpreferred that the subject be a primate and even more preferred that thesubject is a human being. It is also preferred that the switching deviceis a transistor.

[0103] Additionally, the neurostimulator comprises an inductor, actingas a transformer, whereas the stimulation signal is induced in theneurostimulator by inducing electrical current into the inductor, whichfurther induces electrical current in the EEG sensors viaelectromagnetic coupling, and thereby into the subject.

[0104] The neurostimulator can further comprise an optical unit whichfurther comprises a set of light generating devices located in closeproximity to the pupils of the subject. It is preferred that the lightgenerating devices are light-emitting diodes.

[0105] With reference to the accompanying FIG. 1, a preferred embodimentof the present invention is described where a computing device 8 isoperatively coupled to a peripheral device henceforth referred to as aneurostimulator 9, such as through a peripheral cable 10. However, aperipheral cable is not the only method of coupling the neurostimulatorto the computing device. The neurostimulator 9 further comprises aseries of electrical conductors henceforth referred to as EEG sensors11. The EEG sensors 11 consist of at least one positive lead 12, onenegative lead 13 and one ground lead 14. However, the at least onepositive lead 12, one negative lead 13, and one ground lead 14 may alsobe incorporated into one sensor as contacts.

[0106] In a preferred embodiment of the present invention, employingmultiple sets of EEG sensors 11 simultaneously and multiple biopotentialacquisition devices 15 can accomplish acquisition of EEG signals frommultiple sites on the scalp. For clarity, the preferred embodiment isdescribed with for acquisition of EEG signal from one scalp site. AllEEG sensors 11 are connected to the neurostimulator 9 via EEG sensorconnectors 17.

[0107] The neurostimulator 9 can further comprise, as a possible meansof delivering the stimulation signal, an optical unit 16 that iselectrically coupled to the neurostimulator 9 via optical device sensorsconnectors 19. The optical unit 16 can be connected to theneurostimulator 9 by an optical device cable 18. However, other means ofconnecting the optical unit to the neurostimulator are acceptable. Theoptical device further comprises light generating devices 20 located tobe in close proximity to the subject's eyes. In the preferredembodiment, the light generating devices 20 are light emitting diodes21.

[0108] The neurostimulator 9 is operated by any number of possible powersupply 22 sources. To assure electrical isolation for the patient'ssafety, an isolated power supply 23 is utilized in the preferredembodiment. Further, the neurostimulator 9 is housed in a protectiveouter enclosure 24.

[0109] The neurostimulator 9 preferably internally comprises thebiopotential acquisition device and the biopotential acquisition deviceis preferably designed to acquire biopotential data from EEG signaldata, specifically patient EEG, to provide a means for analysis and datastorage of the biopotential data through computational means, generate aneurostimulation signal and deliver the neurostimulation signal to thepatient. It is preferred that a Teledyne A110-2 amplifier be used.

[0110] In a preferred embodiment of the present invention, EEG signalsare acquired with EEG sensors 11 attached to a patient's scalp. At theend of the EEG sensors 11 attached to the patient are contact electrodes25. The EEG signal is delivered to the neurostimulator 9 via the EEGsensors 11, connected to the biopotential acquisition device 15 throughEEG lead connectors 17 and operatively coupled to a biopotentialacquisition device 15 such as a biopotential amplifier or highresolution analog-to-digital converter. To minimize the effect ofexternal electrical noise, any number of circuit or numerical filters 26may be employed in the preferred embodiment. To assure patient safety,the biopotentials are passed through an isolation amplifier 27. Theoutput of the biopotentials, after passing through the biopotentialacquisition device 15, filters 26 and isolation amplifier 27 is acquiredby a microcontroller 28 through analog-to-digital ports 29. Themicrocontroller 28 is operatively coupled to the computing device 8. Onemethod of coupling the microcontroller to the computing device is to usea peripheral cable 10. Control of the neurostimulator 9 is accomplishedby communication between the microcontroller 28 and the computing device8. Further, the objective of biopotential data analysis and storage isaccomplished computationally via communication between themicrocontroller 28 and the computing device 8.

[0111] After analysis of the acquired biopotential, that is, the EEGsignal, the computing device 8 communicates proper stimulation signalparameters, in accordance with the present invention, to themicrocontroller 28. These parameters include signal energy level,frequency of the low frequency component of an AMPWM signal, phaseoffset of multiple signals, start time, frequency offset and durationthrough a user interface. Utilizing a digital-to-analog port 30 on themicrocontroller 28, the stimulation signal is output from themicrocontroller 28 to transistors 31 or similar switching devicescapable of managing the current levels of the stimulation signal.Depending on the mode of stimulation chosen by a clinician, thestimulation signal will be routed to the different means of stimulationsignal delivery, alone or in combination. The parameters for theclinician's choice are set forth above.

[0112] If optical stimulation is desired, the stimulation signal will besent to the optical unit 16 featuring the light generating devices 20 tobe worn by the patient. Any unit capable of emitting light may be usedas a light generating device. This includes, but is not limited to aLED, a light bulb, a low-power laser, etc. Alternately, if EEG lead 11stimulation is desired, where the stimulation signal is delivered to thepatient's scalp via the attached electrodes 25, then the stimulationsignal is sent to an inductor 32 which is designed to induce current inthe EEG sensors 11 from the stimulation signal generated by themicrocontroller 28. In the preferred embodiment of the presentinvention, a plurality of stimulation delivery modes is warranted toallow for clinician choice to further effect successful treatment basedon individual patient needs.

[0113] To assure patient safety, all electronics in the neurostimulator9, including the biopotential acquisition device 15, the filter 26, theisolation amplifier 27, the microcontroller 28 and the transistors 31are supplied electricity by the aforementioned isolation power supply23.

[0114] Finally, regarding the coupling of the components, if a computingdevice is used it is preferably operatively coupled to the processor ofthe neurostimulator via any of a number of means of commonly usedperipheral communications techniques, such as serial communication, USBport communication or parallel communication 10. All remainingelectronics are preferably operatively coupled to the processing device(e.g. microcontroller) in the neurostimulator. The data acquisitioncircuit preferably comprises the biopotential acquisition device 15,filters 26 and isolation circuitry (amplifier) 27. The isolationamplifier is preferably coupled to an analog-to-digital input port onthe microcontroller 28, via electrical conduction paths such as wires orprinted circuit board conductors. The filters 26 are preferablyoperatively coupled to the isolation amplifier 27 via electricalconduction paths such as wires or printed circuit board conductors.Further, the biopotential acquisition device 15 is preferablyoperatively coupled to the filters 26 via electrical conduction pathssuch as wires or printed circuit board conductors.

[0115] EEG leads 11 are preferably coupled to the biopotentialacquisition device 15 via electrical connectors 17, providing conductionof EEG electricity at the scalp to the biopotential amplifier 15.

[0116] A stimulation circuit is preferably coupled to adigital-to-analog port 30 on the microcontroller, in all cases viaelectrical conduction paths such as wires or printed circuit boardconductors. It is preferred that an isolated power supply 23 suppliesall operative power for neurostimulation outputs such as that to theoptical device 16 or the EEG lead stimulation inducing circuitry 32.Electrical output from the digital-to-analog port 30 is preferablyconducted to a transistor 31 that is further coupled to the isolatedpower supply 23. When a signal is received at the base of the transistor31 from the microcontroller 28, the transistor operates to switch onelectricity from the isolated power supply 23 which is further conductedvia electrical coupling to the inductor (stimulation inducing circuitry)32. Current flow in the inductor 32 induces a current in the EEG lead,as described in the specification.

[0117] Alternately, for photic stimulation, the isolated power supply 23is preferably coupled via electrical coupling to two more transistors31, which are preferably operatively coupled via electrical coupling toindependent digital-to-analog ports 30 on the microcontroller 28.Electricity conducted from the digital-to-analog ports 30 to the base ofthe transistors 31 in the photic stimulation circuit has the effect ofswitching on these transistors, further allowing for conduction ofelectricity to the photic stimulation devices, such as LEDs 21. Thephotic stimulation devices are preferably coupled to the transistors 31via electrical connectors 19, thus providing for current flow to thephotic stimulation devices such as LEDs 21.

[0118] Finally, it is preferred that the apparatus operate on a 12 voltpower supply. It is more preferred that the apparatus operate on a 6volt power supply. It is most preferred that the apparatus operate on apower supply equivalent to the lowest power supply requirement of thecomponents used.

[0119] The following references are incorporated by reference in theirentirety:

[0120] 1. “High-frequency stimulation of the subthalamic nucleussilences subthalamic neurons: a possible cellular mechanism inParkinson's Disease”, Magarinos-Ascone C, Pazo J H Macadar O and Buno W.(Neuroscience 2002; 115(4): 1109-17.

[0121] 2. “The spatial receptive field of thalamic inputs to singlecortical simple cells revealed by the interaction of visual andelectrical stimulation”, Kara, Pezaris J S, Yurgenson S and Reid, R C.Proc Natl Acad Sci USA Dec. 10, 2002; 99(25): 16261-6.

[0122] 3. “the anticonvulsant effect of electrical fields”, Weinstein S,Curr Neurol Neurosci Rep March 2001;1(2):155-61.

[0123] 4. “electrical stimulation of the motor cortex in neuropathicpain”, Tronnier v, Schmerz August 2001;15(4):278-9.

[0124] 5. “Centromedian-thalamic and hippocampal electrical stimulationfor the control of intractable epileptic seizures”, Velasco M, VelascoF, Velasco AL, J Clin Neurophysiol November 2001;18(6):495-513

We claim:
 1. A method of treating a neurological dysfunction, whereinsaid method comprises: a) taking a first measurement of the EEG of asubject afflicted with at least one type of the neurological dysfunctionin order to obtain EEG results; b) evaluating the EEG results todetermine whether any region of the brain of the subject possessesirregular activity as compared to other regions of the brain of thesubject; c) determining a dominant frequency of a region of the brain ofthe subject possesses irregular activity; and d) administering ananti-neurological dysfunction therapy to the subject; wherein theanti-neurological dysfunction therapy comprises inducing aneurostimulation signal directed to areas of the brain of the subjectthat correspond to the areas of the brain of the subject that possessirregular activity for a time sufficient to normalize the EEG of theareas of the brain of the subject that possess irregular activity; andwherein additional EEG measurements from the areas of the brain of thesubject that possess irregular activity are monitored during theadministration of the therapy and wherein the neurostimulation signal isadjusted based on any detected changes in the additional EEGmeasurements.
 2. The method of claim 1, wherein the step of evaluatingthe EEG results to determine whether any region of the brain of thesubject possesses irregular activity further comprises the step ofcomparing EEG results from a region of the brain of the subject againstEEG results from the remaining regions of the brain of the subject. 3.The method of claim 1, wherein the step of administering ananti-neurological dysfunction therapy to the subject results inalleviation of symptoms caused by the neurological dysfunctions.
 4. Themethod of claim 1, wherein the step of taking the first EEG measurementsfurther comprises the step of taking the first EEG measurements frommore than one area of the scalp of the subject.
 5. The method of claim1, wherein the step of evaluating the EEG results to determine whetherany region of the brain of the subject possesses irregular activityfurther comprises the step of using the obtained EEG results of step a)to produce a graphic image of the brain of the subject.
 6. The method ofclaim 1, wherein the step of administering an anti-neurologicaldysfunction therapy to the subject further comprises a step of adjustingthe EEG of the regions of the brain of the subject that possessirregular activity to match the predetermined frequency for that regionof the brain.
 7. The method of claim 1, wherein the neurologicaldysfunction is selected from the group consisting of traumatic braininjury, post traumatic stress disorder, post stroke paralysis, posttraumatic brain injury paralysis, cerebral palsy, headache, depression,post chemotherapy cognitive, mood and fatigue disorder, fibromyalgia,memory loss, coma, and attention deficit disorder.
 8. The method ofclaim 1, wherein the neurostimulation stimulation signal comprises a lowfrequency carrier signal and a high frequency pulse train.
 9. The methodof claim 8, wherein the high frequency pulse train is modulated by thelow frequency carrier signal.
 10. The method of claim 1, wherein thesubject is a human being.
 11. The method of claim 1, wherein the step oftaking a first measurement of the EEG of a subject further comprises thestep of taking separate readings at at least 21 different scalplocations.
 12. The method of claim 1, wherein the time is from 1 secondto 1 hour.
 13. The method of claim 1, wherein the neurostimulationsignal comprises a carrier frequency that comprises the dominantfrequency and a frequency offset.
 14. The method of claim 13, whereinthe frequency offset is between −10 and 20 Hertz.
 15. The method ofclaim 8, wherein the neurostimulation signal is an AMPWM signal.
 16. Themethod of claim 1, further comprising the step of administering multipletreatments of the method to the subject.
 17. The method of claim 16,wherein the number of multiple exposures is between 1 and
 40. 18. Themethod of claim 16, wherein a repeated use of the method is avoidedwithin 24 hours of a previous use of the method.
 19. The method of claim1, wherein the method is used to treat more than one region of the brainof the subject that possesses irregular activity.
 20. The method ofclaim 1, wherein the step of inducing the neurostimulation signalfurther comprises the step of inducing the neurostimulation signalthrough EEG sensors attached to the scalp of the subject.
 21. The methodof claim 1, wherein the step of inducing the neurostimulation signalfurther comprises the step of using an optical unit and the step ofinducing the neurostimulation signal induced through photic stimulation;and wherein said photic stimulation is produced by an optical unit wornby the subject, and wherein the optical unit comprises light emittingdiodes, and wherein EEG sensors are attached to the scalp of thesubject.
 22. The method of claim 1, wherein the method is automated. 23.An apparatus for neurostimulating a subject, said apparatus comprising:a) a computing device; b) a neurostimulator that is operatively coupledto the computing device; and c) a series of EEG sensors that are coupledto said neurostimulator.
 24. The apparatus of claim 23, wherein theseries of EEG sensors are configured (1) to be attached to the subject,(2) to measure EEG signals of the subject, and (3) to transmitneurostimulation signals to the subject, and wherein the EEG sensorscomprise at least one positive contact, at least one negative contact,and at least one ground contact.
 25. The apparatus of claim 23, whereinthe apparatus is housed in a protective outer enclosure.
 26. Theapparatus of claim 23, wherein the neurostimulator comprises: a) abiopotential acquisition unit comprising an electric circuit configuredto acquire biopotential data from the EEG signals obtained by the EEGsensors attached to the subject, and to analyze and store the acquiredbiopotential and EEG data with computational means; and wherein thebiopotential acquisition unit is operatively coupled to theneurostimulator; b) a transmission unit configured to transmit thebiopotential and EEG data from the neurostimulator to the computingdevice; c) an I/O unit configured to adjust for a time lag in thebiopotential and EEG data being transmitted; and d) at least oneswitching unit configured to manage a neurostimulation signal.
 27. Theapparatus of claim 23, wherein the neurostimulator further comprises anoptical unit in which EEG sensors are contained, and wherein the opticalunit further comprises a set of light generating units located in closeproximity to the pupils of the subject when the optical unit are worn onthe face of the subject.
 28. The apparatus of claim 27, wherein thelight generating units are light emitting diodes.
 29. The apparatus ofclaim 26, wherein the neurostimulator further comprises: a) at least onefiltering unit; b) an isolation amplifier; and c) a microcontroller; andwherein the EEG sensors are configured to transmit the EEG data directlyto the biopotential acquisition unit; and wherein the isolationamplifier is operatively coupled to the microcontroller and thebiopotential acquisition unit; and wherein the biopotential acquisitionunit is configured to transmit the EEG data and biopotential datathrough at least one filtering unit and through an isolation amplifier.30. The apparatus of claim 29, wherein the at least one filtering unitis selected from the group consisting of a circuit configured to filterdata and a numerical filter.
 31. The apparatus of claim 29, wherein thebiopotential acquisition unit comprises a biopotential amplifier or ahigh resolution analog-to-digital converter.
 32. The apparatus of claim26, wherein the switching unit comprises a transistor.
 33. The method ofclaim 1, wherein the subject is sedated.
 34. The method of claim 1,wherein the subject is medicated.
 35. The apparatus of claim 12, whereinthe subject is a human.
 36. The apparatus of claim 26, wherein theswitching unit comprises an inductor configured to receive a stimulationsignal from the neurostimulator which induce electrical current into theinductor, which further induces electrical current in the EEG sensorsvia electromagnetic coupling, and thereby into the subject.
 37. Themethod of claim 1, wherein step d) further comprises the step ofentraining the EEG signals of the subject.